Thyroid And Parathyroid Agents Flashcards
What are the two hormones that the thyroid produces?
Thyroid hormone and calcitonin -
What are the two thyroid hormones that are produced using iodine found in the diet and what do they do?
Tetraiodothyronine or levothyroxine (t4)- 4 iodine atoms
And
Triiodothyronine or liothyronine (T3)- 3 iodine atoms
Thyroid cells remove the iodine from the blood, concentrates it and prepares it for attachment to tyrosine, an amino acid. Which in turn, makes our thyroid hormone.
Must ingest enough iodine in order to make these hormones.
What are the functions of thyroid hormones?
-Regulate the rate of metabolism
-Affect heat production and body temperature
-Affect oxygen consumption, cardiac output, and blood volume
-Affect enzyme system activity
-Affect metabolism of carbohydrates, fats and proteins
-Regulate growth and development
What controls the thyroid gland to release hormones?
The pituitary gland. - when TH is low, it will release:
- thyroid stimulating hormone
-T3 and T4 will then circulate in the blood stream.
-pituitary gland will sense the t3 and t4 which will then decrease tsp production so then the thyroid will not secreted more.
What regulates the pituitary gland?
Hypothalamus - tsh releasing hormone- trh
Thyroid stimulating hormone releasing hormone.
How many types of thyroid dysfunction are there and what are they?
Hypothyroidism: Underactivity - is more common
Hyperthyroidism: Overactivity
What are the causes of hypothyroidism (Underactivity)?
-Absence of thyroid gland
-Lack of sufficient iodine in the diet to produce these hormones needed level of thyroid hormone - have iodine salt here in America
-Lack of sufficient functioning thyroid tissue due to tumor or autoimmune disorders- most common dz- hashimotos
-Lack of TRH related to a tumor or disorder of the hypothalamus
-Lack of TSH due to pituitary dz
How would you define hyperthyroidism?
Excessive amounts of thyroid hormones are produced and released into circulation-
What is the most common cause of hyperthyroidism?
Graves dz.
What are the signs and symptoms of hypothyroidism?
Vague and there are many.
Some include obesity and fatigue
What are the Signs and symptoms of hyperthyroidism?
-Increased body temperature, tachycardia, thin skin, palpitations, hypertension, flushing, intolerance to heat, amenorrhea, weight loss, and goiter.- enlargement of the thyroid. Over stimulated by tsh.
Use of thyroid and parathyroid agents across the lifespan: CHILDREN
Hypothyroidism: Hyperthyroidism: Hypercalcemia: seen in pts with cancer
- Levothyroxine- -Methimazole. -Rare
- higher doses. -Don’t use: -Bisphosphonates
- monitor thyroid labs. Propylthiouracil. -Monitor calcium levels
- monitor growth and development Radioactive agents
Use of thyroid and parathyroid agents across the lifespan: ADULTS
-Hypothyroidism: Lifelong, monitor thyroid labs, Pregnancy and lactation: levothyroxine
-Hyperthyroidism: Side effects worse with methimazole- can cause bone marrow suppression greater go and cns effects, sodium iodide can effect fertility, pregnancy: Propylthiouracil- less drug passes through placenta, do not use in lactation.
-Hypercalcemia: Osteoporosis, Monitor calcium levels, Calcium and vitamin D supplements, Pregnancy: DO not use bisphosphonates during lactation.
Use of thyroid and parathyroid agents across the lifespan: OLDER ADULTS
Hypothyroidism: Screen regularly, start low go slow, Levothyroxine, Monitor response: Thyroid levels, cardiac effects
Hyperthyroidism: sodium iodide- good option, monitor for hypothyroidism- within a year of antithyroid medication.
Hypercalcemia: Dietary deficiencies: calcium and vitamin D supplements, osteoporosis: BISPHOSPHONATES-help move calcium back into bone, renal impairment, monitor calcium levels.
What are the names of the thyroid hormones?
-Levothyroxine
-liothyronine
-Liotrix
-Thyroid Desiccated- dried animal thyroid tissue- pigs important to know cultural religion of patients.
Actions of thyroid hormones
Increases cellular metabolism - which increases o2 consumption, respirations, hr, increases rate of body tissues which increases rate of fat protein carbohydrate metabolism effecting growth and maturation. Increases cellular metabolism in all areas of our body.
Thyroid Hormones indications
-Hypothyroidism- organisms still working
-Myxedema coma- have a severe hypothyroidism- decreased mental status and other symptoms of slowing of functioning- medical emergency, high mortality rate. - organisms not working
-Pituitary TSH suppression in treatment of euthyroid goiters- goiter even tho th are normal, if given Th then the pituitary would slow release of it.
-Management of thyroid cancer;
-Thyrotoxicosis in conjunction with other therapy - hyperthyroidism where there are signs and symptoms- why would we give TH?- if we give external TH it would have more circulating then maybe PG will stop the release.- monitored very closely
Why would an acute MI be a contraindication to giving this drug?
Because it can cause cardiac effects, - if they have hyporthyroidism and it is complicating MI then we might give supplements. This is called MI complicated by hypothyroidism.
Why would thyroidtoxicosis be a contraindication to give thyroid hormone to?
hyperthyroidism where there are signs and symptoms- why would we give TH?- if we give external TH it would have more circulating then maybe PG will stop the release.- monitored very closely